Hypericum Strong

The Cover Story

If you’re at a party and the centerpiece has red or yellow fruit with a green leafy collar, the florists might tell you this is “coffee berry,” but that’s off base; it’s not coffee, not even related. That filler material is likely Tutsan, the Old World Hypericum androsaemum, a plant long cultivated, recognized and used in various herbal cures. Hypericum androsaemum is the only Hypericum that matures fleshy fruit; all others produce dry capsules. (Image below copied from FloraSourceDirect.com)

Despite herbal uses of Tutsan, if someone in the nutraceutical trade recommends Hypericum for any concern, from depression and menopausal symptoms to ADHD, the claim accompanies dried, powdered foliage of another plant, St. John’s Wort, Hypericum perforatum, a Eurasian native that’s made its way as a weed in many other parts of the world. This same plant might be prescribed should you be in the market for something to drive out demons. Your chance comes in late June, on St. John’s eve, when it would be especially handy to have fresh flowering branches at hand.  June 23rd would be a good time to deal with that delayed exorcism.

It’s obvious these plants have long been a part of Western culture, connecting us to an era when ancient Greeks crowned and wreathed religious icons with boughs of these golden flowers thought to ward off evil, a practice reflected in the name: Greek hyper, above, and eikon, image, alluding to festive adorning of religious figures. Those cultural associations seem to have migrated with the plants from the Mediterranean to England, and from there to other parts of the world, where Hypericum perforatum (and even other local species) are often imagined as possessing powers proper most especially to the night preceding 24 June, that is, to Midsummer Eve.

The image above is Elizabeth Blackwell’s, published in her 1737, A Curious Herbal… (Vol I, Plate 15, Courtesy Missouri Botanical Gardens). Below, you can read the accompanying text from Blackwell.

Her text reflects the work of Joseph Miller, whose unillustrated treatment in Botanicum Officinale…, 1722, was basically an updating of Samuel Dale’s 1690 Pharmacologia. Blackwell and Miller were both associated with London’s Chelsea Physic Garden; Miller’s treatment of Hypericum is shown below, courtesy of an on-line image from the Wellcome Collection. Reading his uses, the plant seems a panacea.

The magical and herbal Hypericum perforatum, and the decorative but also herbal Hypericum androsaemum are just two plants among the over 500 Hypericum species you might investigate for amusement or utility, that is, if you can identify which is which.  It’s a large, varied, and sometimes indecipherable group of plants, corralled in this one genus despite determined efforts by generations of botanists to wrest the group apart.  I say that because the Botanical closet is packed with over 40 generic names proposed since Linnaeus published Hypericum in Species Plantation (1753).  In fact, Linnaeus himself proposed two other genera (Sarothra and Ascyrum) in the same publication, a fourth shortly after.  Why have so many names, so many attempts at subdivision, been rejected?  What holds these plants together?

The Main Story

Though large and varied, Hypericum remains nearly intact as a genus because the flower and fruit are so similar from one type to another.  And so far, genetic studies have reinforced that perceived similarity. Volume II, Flora of Florida (2015) does chip away at the monolith, accepting Rafinesque’s genus Triadenum, as segregating the pink-flowered species with fasciculated stamens from Hypericum.  That altered classification, however, is not reflected in the ISB database (they are all Hypericum in the Plant Atlas).

In Florida, you can fairly confidently identify a plant as Hypericum if:

  • it’s an an herb or shrub with simple, entire, opposite leaves – leaves that are comparatively small, generally less than 3 cm;
  • the modest yellow flowers (only 3 of  the 34 species reported in the ISB Florida Plant Atlas have pink flowers) produce 4 or 5 separate petals, each flower:
    • bearing a simple superior ovary with either a single style, or dividing into as many as 3 or 4 styles
    • loaded with many stamens
  • the superior fruit mature as small, dry capsules that are often retained among older foliage

I’ve discovered that discriminating among the 30+ native species you might encounter in Florida can be difficult.  Keys will segregate the three Florida plants with pink petals (now treated in Flora of Florida as Triadenum), leaving the 30+ yellow-flowered plants to be dealt with utilizing the following characters:

  • Petioles (which may be petiolate, sessile, with or without a demarkation)
  • Presence and nature of glands in the leaf blades
  • 4- versus 5-merous sepals and petals
  • Styles parted into 2 or more segments – a problematic character, which can be variable
  • Leaf size, shape, and texture
  • Leaf surface (glabrous, pubescent, glaucous)
  • Sepal character, spreading versus clasping
  • Sepal size, shape, and symmetry
  • Presence of short branches at nodes (fasciculation)
  • “Lining” (basically decurrent tissue) along young stems
  • Bark color and character
  • Plant height
  • Stem woody versus herbaceous nature
  • Flower size

Some alternatives posed in the keys make for difficult choices.  For example, in examining plants in Franklin and Liberty Counties, I haven’t been able to distinguish between plants with larger stems that have peeling bark vs. spongy bark, characters used to determine whether a specimen is Hypericum chapmanii, Hypericum fasciculatum, or Hypericum nitidum.  I’ve not seen specimens of plants that have a “definite articulation zone” at the leaf base as compared to those that lack such a demarcation, which means I lack the appreciation of that distinction.  And I don’t have the experience to determine when a plant has several, short non-flowering leafy branches versus those that lack such branches.

A curiosity that may be useful for field identification comes with the broad range of vegetative characters that are critical to determination, certain species actually mimicking the appearance of other, unrelated kinds of plants, an observation evidenced by many specific epithets – Gentianoides, Myrtifolium, Cistifolium, Apocynifolium… In the field keys and descriptions below, you’ll discover in a few circumstances that I resort to calling out similarities as a convenience. Hypericum gentianoides, for example, looks like Scotch Broom (Cytisus, Fabaceae) and the plant of H. harperi looks, for all the world, to be a Flax (Linum).

Floristic keys, of course, are usually constructed based on herbarium specimens, examined at a well-lighted table, using a good dissection scope, and absent biting flies. The characters available in an herbarium may not always work in field identification, and for these purposes I’ve devised my own “field key” to plants I’ve examined around the Central Panhandle, based on features that work for me with fresh material.  The summer season is half consumed, and I still account for two-thirds of the species reported from the Apalachicola region . But I’m documenting the different kinds, working to locate and examine additional plants. Perhaps other plant enthusiasts with more experience in the region can help expand my understanding. So which plants am I missing that are reported from the regional flora: Here’s the list of no-shows:

  • Hypericum apocynifolium – the northerly flora
  • Hypericum canadense – a leafy version of GENTIANOIDES?
  • Hypericum chapmanii – FASCICULATUM complex
  • Hypericum denticulatum Western Panhandle
  • Hypericum drummondii – the northerly flora
  • Hypericum gymnanthum – a stretched-out CISTIFOLIUM?
  • Hypericum lissophloeus – Bay Co., rare, locality data withheld
  • Hypericum nitidum – FASCICULATUM complex
  • Hypericum nudiflorum – leafy, northerly
  • Hypericum punctatum – nothing recently collected
    • The 3 species below are pink-flowered, and treated currently as Triadenum
  • Hypericum (Triadenum) tubulosum – leafy, cited specimens older, from MS
  • Hypericum (Triadenum) virginicum – leafy
  • Hypericum (Triadenum) walteri – leafy, reported from Cypress creek edges near Wright Lake, 1991, located but past flowering

To date (August 2023), below I include a terse index to the yellow-flowered plants (Hypericum sensu stricto), followed by my working criteria for field identification of plants I have encountered and documented. Super-useful characteristics are highlighted in bold font.

  • Flowers with 4 petals & 4 sepals
    • Sepals equal in size – MICROSEPALUM
    • Sepals unequal, outer pair large & cordate
      • Plant ground-cover in habit – SUFFRUTICOSUM
      • Plant an open shrub, to 1.2 m
        • Leaves green, papery; shrub many-branched, inner sepals very reduced and reflexed – HYPERICOIDES
        • Leaves ± glaucous, shrub coarse, open, with few branches
          • Leaves clasping – TETRAPETALUM
          • Leaves broadly attached – CRUX-ANDREAE
  • Flowers with 5 petals & 5 sepals, upright herbs with soft, green stems (becoming thickened & woody basally in HARPERI)
    • Leaves ascending, narrowly-lanceolate to scale-like and clasping (GENTIANOIDES), stems green, annual, less than 0.5 m, multi-branched
      • Stem and leaves green to base multi-branched annual herb, leaves appressed, scale-like, flowers tiny, 5-7 mm across – GENTIANOIDES
      • Stem and leaves a bit glaucous, branching at the top as inflorescence, flowers about 2 cm across, petals longer than leaves – HARPERI
      • Stem and leaves covered with stiff, short hairs – SETOSUM
    • Main Stem Leaves broader, almost shield-like, very soft & herbaceous (the texture of Venus’s Looking Glass), spreading – MUTILUM
  • Flowers with 5 petals & 5 sepals, stems fibrous or woody, leaves tough or leathery
    • Leaves broad, spreading
      • Flowers smaller than leaves, rampant along edges – CISTIFOLIUM
      • Flowers as large as leaves, uncommon, in swamps – MYRTIFOLIUM
      • Leaves deep blue-green, Plant of glades and drier soils, Northern edges of Flora, FRONDOSUM
    • Leaves almost needle-like, but with apparent blades – GALIOIDES
    • Leaves  acicular
      • Low-branched shrub, Leaves short
        • Leaves consistently 6 mm or less, ascending – TENUIFOLIUM
        • Leaves variable, plant of wetlands – BRACHYPHYLLUM
      • Shrub branching at knee-length or above
        • Trunk-forming, reaching 3-9’ – FASCICULATUM Complex
        • Thin-stemmed, under 2’ tall – EXILE

4-Sepaled, 4-Petaled flowers

Flowers with sepals about equal to each other in size, petals and leaves of similar size – Hypericum microsepalum

Hypericum microsepalum is my tentative identity to the most common Hypericum I encountered in March and April. The multi-branched, thin-stemmed but woody plant (a small shrub) seldom tops a height of 50 cm (20″). Stems are covered densely with small, flat leaves.

Hypericum microsepalum seems to have flowered earliest this growing season, and continues into summer with successive flushes, sometimes nearly covering individual branches with small flowers. Images below are from mid-March, in the Box R WMA west of Apalachicola.

Checking characters against keys, I find that examining the pistil with a hand lens to determine the number of styles can be difficult; there sometimes appears to be a single style (as opposed to three or four). If fruit capsules are available, the number becomes a more useful character. In the buds of fresh material, sepals are positioned upright, adjacent to but standing apart from the unfurled petals. When open, the four petals show as individually asymmetric, and slightly unequal in size. The nearly-linear sepals, similar to each other in both width and length, clearly stand out between petals in the open flowers. Note in the photograph below the sepals are clearly visible, and about half the length of the petals. Also note the twisting and asymmetry of the petals.

In Hypericum microsepalum, the flowers are much larger across than the length of the longest leaves, indeed, the length of individual petals is about that of the larger leaves.

A useful (and odd) field character involves the appearance of new growth, in which young leaves remaining somewhat appressed, folded upward toward the tip, appear a bit gray or glaucous. The impact is that of a plant undergoing water stress. If you see a short, small-leaved, densely-shrubby Hypericum that looks like it’s suffering, that’s likely to be H. microsepalum.

Flowers with 4 petals and 4 sepals, sepals asymmetric, the outer pair cordate, much larger than the inner, folded up against developing flower buds, leaves glaucous in some.

Plant a ground-cover, prostrate to low, tiny, few-branched, occurring in small patches on the forest floor (weakly rhizomatous) – Hypericum suffruticosum

Hypericum suffruticosum takes the prize for forest floor miniature. I find this plant in pine forest with open soil available, which has meant (at least so far) it shows up in areas that are regularly burned, and is most visible where the cover of oak or wiregrass has not filled in completely. The flower resembles those of Hypericum crux-andreae and H. tetrapetalum (without the rest of the shrub), and the overall plant, simply growing (rhizomatously) matted on the ground, looks as though someone plucked an inflorescence from its larger cousin and dropped it to the forest floor. Plants I’ve encountered are minuscule, with flowers much larger than the leaves. Like H. tetrapetalum, the four sepals pair off as an inner small set opposite one another and a larger, cordate outer set

As the keys indicate, this is considered a “woody” plant as opposed to being herbaceous, but that’s true only from the viewpoint of texture. The stems can be several nodes tall, with the one shown below flowering at over 12 cm. It’s not enough wood to get you very far.

Plant a shrub with thin, woody stems, to 1.4 m (4 ft), though normally a meter or less

Shrub about 0.5 m, leaves thin, not glaucous, the smaller pair of sepals highly reduced and reflexed – Hypericum hypericoides

Flower of Hypericum hypericoides

Hypericum hypericoides, which I’ve identified from plants in Box R WMA, Tate’s Hell State Forest, and ANF, keys out in a way I fear will prove difficult. The difference used in floristic keys, 2 styles in H. hypericoides (versus 3 styles for flowers of H. tetrapetalum & H. crux-andreae) is dicey. Hypericum tetrapetalum style branches develop incompletely at times, making the number of branches a difficult character for me.

Hypericum hypericodes, showing the consistenly “bowtie” configuration of petals

Having examined photographs and specimens in ISB, Hypericum hypericoides resembles H. tetrapetalum in sepal structure (with the larger, cordate outer sepals), but the inner sepal is greatly reduced (as compared to others).

Pistil of Hypericum hypericoides. Note the highly-reduced inner sepals (the whitish, recured segment just below the pistil…) Also, note the short styles.

Moreover, Hypericoides bears non-glaucous leaves that are much smaller and twice as dense along the stems, in shape having distinct (cuneate) leaf bases and smaller flowers in which the 4 petals often orient to form an “X” shape. David Roddenberry calls these “bowtie” forms.

Flowers of Hypericum hypericoides

Encountering living plants, the architecture and habit differ greatly, H. hypericoides being shorter, shrubbier (more greatly branched), with much denser spacing of leaves than H. tetrapetalum.

Foliage of Hypericum hypericoides

And, at least from encounters to date, the petal configuration is consistently of the “bowtie” sort, with smaller, more thinly-textured petals.

Hypericum hypericoides flowers

Shrub modestly branched, newer foliage glaucous, flowers larger than a penny – Hypericum tetrapetalum & Hypericum crux-andreae

I’ve identified Hypericum tetrapetalum as an open, coarse shrub with glaucous foliage. The shape and texture of its leaves are distinctive, along with the prominent heart-shaped outer “sepals” that enclose buds, reflex during flowering, and then fold back against the developing fruit. It’s an attractive plant, in a lanky sort of manner. The trouble is that this description also fits H. crux-andreae, which is said to differ in details of foliage, with leaves not as clasping, lacking “gland-like auricles” (according to the Flora of North America key).

To me, the individual flowers of H. tetrapetalum and H. crux-andreae are the prettiest of local plants in the genus, in color, a softer yellow, and in impact, larger than those of others flowering in the area. And the foliage, though sparse compared to it’s regular companion, H. microsepalum, is lovely – large glaucous leaves with rounded tips and broad, almost clasping bases.

Hypericum tetrapetalum and Hypericum crux-andreae are, in habit and flower, very similar, the differences showing most in foliage. The plant we call Tetrapetalum shows somewhat clasping, glaucous foliage, the leaves broadly ovate and broadly-attached. In populations that frequently are near to one another, if not intermixed, we find the vegetative form of H. crux-andrae, in which the leaves are not conspicuously glaucous, and in shape are more oblong, with a constricted, nearly petiolate point of attachment. To give a sense of my impression of their essential aspect, Crux-andreae seems to represent hybrid characteristics of Tetrapetalum and Hypericoides. This is no claim it’s of hybrid origin, rather in the goody bag of Hypericum characteristics, the stems and foliage of Crux-andreae share similarities with Hypericoides, while the flowers are more similar to those of Tetrapetalum. Interpret that how you wish.

Hypericum tetrapetalum type, with glaucous leaves and a full-sized leaf pair just below floral pedicels (3 styles visible)
Hypericum crux-andreae, with oblong, nearly petiolate leaves, and smaller leaves below flower pedicels

In recent field studies, I discover one character difference that might be useful, if it holds up to further inspection. The plant that seems to represent Tetrapetalum maintains leaf size up to flowering, the last pair of leaves below the flowers being at least as large as, or even larger than the outsized cordate outer sepals. However, plants I examined that appear to conform to the description of Crux-andrae have a reduced pair of leaves below the flower, with the result that the cordate outer sepals are larger than the last leaf pair. If these plants remain as separate species, it is truly a case of twins. There could be good reason to combine them, describing the two as formae. In that case, the name H. crux-andreae, having been described validly in 1766 would have seniority over H. tetrapetalum, which was described in 1797.

A plant flowering in late July at BoxR, seeming to show foliage type of Hypericum crux-andreae
Hypericum crux-andreae?
Hypericum crux-andreae?

Petals and Sepals 5

Herbs, annual or rhizomatous (hardened or wirey stems, but not woody shrubs)

Leaves practically scale-like, appressed-clasping; Plant annual, with green, delicate, multi-branched vertical stems. – Hypericum gentianoides

Hypericum gentianoides – what a funny and distinctive small plant. Early in summer, it springs up in waste areas and along the edges of dirt roads, not promising to be a Hypericum at all. Eventually, following enough branching to have the look of a tiny Scotch Broom, or a frail green Ephedra, or a multi-branched Equisetum, the very tiny and delicate, short-lived flowers betray this as a Hypericum.

Hypericum gentianoides flower

Early workers were perplexed with this herb also. Linnaeus, 1753, gave the plant its own genus, naming it Sarothra gentianoides. The specific epithet came from Gronovius’s earlier name, Gentiana caule ramisque ramosissimis…. Plukenet had called it the miniature Centaurium (Centaurium minus spicatum, angustissimo folia), a plant in the Gentian family. [See the text from Linnaeus, below]

Entry for Hypericum gentianoides in Species Plantarum, 1753
Hypericum gentionides in habitat, showing how the plant melds into the the local vegetation
Hypericum gentianoides

Leaves lanceolate or broadly elliptic to oblong (not needle-like), Branching with flowering, herbaceous and annual, or rhizomatous and wand-like

Leaves below inflorescence broadly ovate, softly-herbaceous; flowers tiny (1/4″) Hypericum mutilum

On first encountering Hypericum mutilum, my thought was that it’s like a leafy version of Hypericum gentianoides, being as distinctive and herbaceous, and showing up in similarly disturbed sites.

The highly-branched, delicate inflorescence of Hypericum mutilum

The plant is more softly-herbaceous than Gentianoides, with short main stems that are highly branched, the vegetative nodes (below the inflorescence) outfitted with pairs of broad, soft, spreading leaves. The flower is similar in size to that of Gentianoides, tiny and delicate, with three capitate stigmas on modest, divergent styles.

Flower of Hypericum mutilum

The following photographs (with very shallow depth of field) illustrate the comparisons between pistils of Gentianoides and Mutilum.

Hypericum gentianoides (left) and H. mutilum (right)
Hypericum gentianoides, the ovary is shorter than the styles; sepals are shorter than petals
Hypericum mutilum, the ovary is 2-3x the style length, sepals are longer than petals

Mutilum is one of the Hypericums with “accrescent” sepals. If you glance down the stem at flowers that have passed into fruiting, you’ll see three outer sepals have enlarged, eventually clasping the fruit with a shield-shape. This is a wonderful and diagnostic feature.

Expanding (accrescent) sepals of Hypericum mutilum, eventually clasping the fruit

Leaves narrowly lanceolate, ascending to clasping; Flowers larger than leaves; Plants of regularly inundated sites – Hypericum harperi if glabrous, Hypericum setosum if hairy

I had been watching a location at which Hypericum harperi was collected thirty years ago, when I found extensive stands of plants matching this description a few miles north, just west of Sumatra. These plants are distinctive, appearing to be herbaceous, in habit they are like Cistifolium, but with narrowly lanceolate, ascending leaves, the more apical leaves almost clasping the stem. Flowers of Harperi are very different from those of Cistifolium, being much larger as compared to the leaves, being produced singly, rather than in flat-topped arrays, and showing three long styles (protruding beyond the shock of stamens, closer to the petals), each branch with a capitate (or at least enlarged) stigma. The flaring styles and enlarged stigmas of Harperi and Setosum are distinctive.

Flower of Hypericum harperi, showing protruding, somewhat-capitate styles

Hypericum setosum, in size and habit, is similar to H. harperi, with three significant vegetative contrasts: H. setosum leaves and stems are stiffly pubescent (the only hairy Hypericum in our flora), its leaves are broadly lanceolate and larger, and stems emerge from lower nodes following formation of the terminal inflorescence.

Foliage of Hypericum setosum
Flower of Hypericum setosum, stacked image showing stamens, 3 styles, and petals
Profile, showing styles in Hypericum setosum flower
Hypericum setosum pistil, with stamens, some sepals, and petals removed

Flowers small (typically with breadth half the leaf length, but at least 1/2″ across), born in flat-topped terminal clusters; Common along roadsides and swales. Plants flowering as single-stemmed young individuals, and as fully-developed shrubs of nearly 1 meter – Hypericum cistifolium

Hypericum cistifolium makes the list as being commonly present in areas that are not boggy, though it is present in swales (in the state park on Saint George Island) that are occasionally inundated as well as marshy areas. It’s a bit cosmopolitan.

It’s also the native Hypericum most frequently sold in nurseries. The plant must germinate and establish rapidly, as I’ve encountered large colonies of seedlings (or perhaps rhizomatous sprouts, which I need to investigate).

Key features for field identification include:

  • the habit, erect and spreading, less than 1 m tall
  • the leaves, which are ovate-elliptic, with rounded bases (sessile) and often as much as 3 cm long, and evenly specked with pellucid dots (clear glandular spaces visible with transmitted light)
  • the small flowers (about 12 mm across) produced in terminal, flat-topped clusters (their breadth being less than half the size of larger leaves), showing unequal sepals
Hypericum cistifolium
Hypericum cistifolium
Hypericum cistifolium, showing 2 larger, and 3 smaller sepals

Shrubs, woody

Plant an open, modestly-branched woody shrub, Flowers larger than leaves, each petal almost as long as an individual leaf. Growing in swampy clay soils – Hypericum myrtifolium

I’ve encountered a single population of Hypericum myrtifolium comprising about 15 plants, all of which are modest, open shrubs no taller than 6o cm. Individuals in that colony are scattered around the edges of a small Cypress swamp, along slightly higher ground that is often inundated, and always muddy.

The plants produce handsome flowers and fruiting structures in terminal inflorescences, each with sepal spread and petal breadth much broader than that of a leaf pair. As an important note, the plant I’ve identified here as H. myrtifolium bears significant similarities to plants I’ve purchased of Hypericum frondosum (see the following description.)

Foliage of Hypericum myrtifolium, clasping the stems – a key distinction from H. frondosum

Shrub with broad, comparatively large deep green leaves, varying to blue-green, Plant more northern distribution, just touching into Florida in Jackson and Gadsden Counties, of drier glades – Hypericum frondosum

Hypericum frondosum, a wild-collected from from Missouri

Barely represented in the Apalachicola Flora, I know Hypericum frondosum from two plants acquired at nurseries. One is a wild type from Missouri, the other the selection ‘Sunburst’ introduced by Richard Lighty at Delaware’s Mt. Cuba Gardens, is available in regional native plant suppliers.

Hypericum frondosum, Missouri type

The plant is varyingly described as evergreen to deciduous, which betrays it’s more northerly associations. It’s also worth noting the plants I acquired are similar in flower and leaf, but produce very different flowering branches and sepals – a note of concern as to identification and variability of this species. Both foliage and flower are most similar to our swamp native, Hypericum mytrifolium, but the calyx of H. frondosum is much larger and very “leafy”.

Fruit and Calyx of H. frondosum ‘Sunburst’
Fruit and Calyx of H. frondosum Missouri wild type
Foliage of H. frondosum ‘Sunburst’
Foliage of H. frondosum Missouri wild type

Leaves almost needle-like, but bearing noticeable blade tissue either side of the main vein – Hypericum galioides

When you read further, you’ll find Hypericum brachyphyllum and Hypericum fasciculatum. If I took the look of the flowering stems and lower-branching, shrubby habit of H. brachyphyllum, combined that with the leaf length of H. fasciculatum, and then made the leaves more blade-like and not so needle-like, I’d have created a plant very similar to H. galioides. To this moment, I haven’t encountered Hypericum galioides in Franklin County, at least not near the coast. It is, however, very prominent along FL State Route 20 west of Blountstown, and into Apalachicola National Forest as far south as Wilma.

Showing the narrow, but still blade-like leaves on Hypericum galioides

Leaves needle-like, woody, well-branched shrubs

Leaves seldom longer than 6 mm (well less than 1 cm), plant modestly branched. growing in drier pine soils.

Shrub less than 0.5 m, dry sands in forest or inter-dunal (on SGI, occurs in masses); Openly-branched, Longest leaves 6 mm, somewhat ascending – Hypericum tenuifolium

An image in the ISB database of a Hypericum tenuifolium specimen from Franklin County collected in 1988 by Godfrey was labelled as Hypericum reductum, which is now considered synonymous to Hypericum tenuifolium (as has been annotated by Hansen.) The Franklin County specimen was collected on the mainland, in Eastpoint, at a site recently cleared for sale. That location is on the mainland, 4 miles north of the Saint George Island specimens shown in these photos. Having searched, I haven’t located this plant on the coast.

These plants are unique in character, with the smallest leaves among of any of the woody and shrubby Hypericums. Specimens on SGI are neither tall nor densely branched, and they grow in relatively dry sites. I first encountered H. tenuifolium as scattered specimens in the pine forest, but later found a massive population in swales between ancient hind dunes and the forest – in that zone between the two. Associates are Conradina canescens, Seymeria, Cnidoscolus, and Polygonella (Polygonum) polygama. The plant bears small flowers, yet each flower is still broader than the length of any leaf.

Shrub of 0.5-1 m, common in wetlands, often occurring with H. fasciculatum; longest leaves can reach 1 cm or more in specimens in some locations; plant densely branched and foliated – Hypericum brachyphyllum

Casually glancing at dense stands of tall shrubs (1-2 m) in boggy areas, I was having true difficulty distinguishing among the needle-leafed Hypericums that are present. Plants with longer leaves key to Hypericum fasciculatum, while those with short leaves key to Hypericum brachyphyllum. But Ecologist Ann Johnson explained that among the boggy zone Hypericums, H. brachyphyllum will re-sprout from its roots following fire, while Hypericum fasciculatum re-establishes through seedlings, so leaf-length can’t be the only useful character.

I’ve visited numerous populations this year (2023), and have my own clues to the identity of H. brachyphyllum, though baffled that it occurs so commonly in mixed populations with the plants I’m calling H. fasciculatum. Follow my journey by examining the photographs below:

The pair of photos (above) were taken in two locations, both areas of wet to boggy soils, at least 30 miles apart. The photo to the left was near Sumatra, while the right-hand photo is from Box R, near Apalachicola. In each photograph I’m holding two specimens, and in each instance, the stem on the left correlates with descriptions of H. brachyphyllum while the stem to the right matches characters of H. fasciculatum. Below, I posted a single image, showing a sample of the plants taken from a mixed population (under permit) in Box R, Hypericum brachyphyllum on the left and H. fasciculatum on the right.

Hypericum brachyphyllum has congested, short leaves. The new foliage is conspicuously glossy, appearing resinous (though I detect no resin). And the flowers are a bit smaller than those of H. fasciculatum. Examine the photograph below:

Most importantly, plants of Hypericum brachyphyllum, branch low to the ground, the crown formed from numerous stems, while plants of H. fasciculatum usually produce a single stem that branches into a dense shrub well above the ground. Compare the two photographs below, showing a plant of H. brachyphyllum on the left (1st, on small screen), and an image of H. fasciculatum (right side photo, 2nd on small screen)

At this moment, the characters that work for me rely heavily on gestalt. Hypericum brachyphyllum stem tips are congested, tight, with shorter leaves and (at least when producing flowers) a whitish sheen to the cylindrical clustering of buds and flowers. There is a glimpse of glossiness about the foliage, unlike any other Hypericum in our area. Here are a few photos from a single location of shrubs marked by those characteristics:

Of course, the most bothersome aspect in these observations is the common co-occurrence of H. brachyphyllum and H. fasciculatum. What’s going on here? But that isn’t the only worrisome concurrence. The other nagging concern is similarity between H. brachyphyllum and H. tenuifolium. If I handed you a short stem of each, in flower, you might readily argue they are conspecific. In the field, habit and habitat are quite distinct, but I imagine pressed specimens could pose difficulties for identification. The similarities make me wonder if the day might come when the two taxa are regarded as varieties of the same species.

Below I’ve included photos of the two plants, side-by-side. In each image, Hypericum brachyphyllum is on the left, with Hypericum tenuifolium sample on the right:

For added emphasis on the value of field characters, below are the two plants in nature. Hypericum brachyphyllum is shown in the photo on the left (1st on small screen), while Hypericum tenuifolium is featured in the photograph to the right (2nd on small screen).

Just below this text, you’ll find a 3 minute video giving a bit more detail. concerning distinctions between Hypericum brachyphyllum and H. tenuifolium.

Shrub commonly arising as single-trunked, branching at about 0.5-0.7 m above ground, often in standing water, or at least in wet edges – Hypericum fasciculatum complex

Establishing and persisting as colonies of high-branched, one to few-trunked small trees in wet soils and standing water Hypericum fasciculatum complex

As a newcomer, lacking clear understanding as to differences, the plant I’m referring to as Hypericum fasciculatum includes Hypericum chapmanii. Though people much more experienced are clear in the differences; it will be a while before I’m able to spot a distinction.

I detailed some observations in comparing Hypericum fasciculatum to H. brachyphyllum, but must give the plant its own attention, minimally to explain my concerns (following) about Hypericum exile. Below you’ll see photos I ascribe to H. fasciculatum:

In the broadest taxonomic sense, this is the identity I give to Hypericums that look like small trees in boggy and swampy areas. They are basically densely-branched shrubs on stilts, the woody stems forming as part of a growth process producing tall leaders that branch at about 0.5-0.7 m. The plants can persist over long periods, at least as long as Titis don’t close in or the understory isn’t reduced to ashes by fires,. Their evergreen presence creates floating hedges 1-2+ meters tall, often seen reflected in standing water. And you’ll see them as part of the nearly impenetrable bramble that lines borrow ditches throughout the wetter flatwoods. It has to be said that in a few mixed populations with H. brachyphyllum, there’s some sense of hybrid forms between the two.

Thin-stemmed, modest somewhat woody plants branching at about 0.5 m, never developing a shrubby crown, establishing as individuals (not colonies) in moist soils but not in wet edges or standing pools – Hypericum exile

That brings me, finally, to the issue of Hypericum exile. I may have never really encountered this taxon. Along forest roads, south of Sumatra, I encounter small very modest and disparate stands of wand-like Hypericums, with modest top-branching and irregular leaf length, the longest reaching 17 mm. The plants convinced me they could be keyed to H. exile. But we are talking about some fairly subtle differences that relate to subtle aspects of stem and leaf character, difficult to decipher from mere words.

I’ve returned to the area on several occasions, and those plants, growing in the “mow strip” of Forest Service roads, either vanished, or appear to continue antlering, developing greater branching. So I’m left wondering if the plants I so fervently hoped would prove to be Hypericum exile are simply juvenile Hypericum fasciculatum. This will take a while to decipher. I’ll need to see living plants, in situ, that are bona fide Hypericum exile, a difficult challenge in that the plants are threatened and location data are not revealed.

A Twist in the Plot

Flowers of the yell0w-petaled Hypericums have a sameness that helps identify the group, but leaves taxonomists with a small cache of characters in constructing keys to identification. Numbers of sepals and petals, sepal morphology, number and nature of stamens, and flower size are useful. The number of styles , a character used in several floristic keys, has proven problematic in my own observations. Flowers clearly identifiable as Microsepalum and Tetrapetalum, for example might show one or two styles, the number becoming greater as fruit mature and the carpels separate. This contrasts with keys that segregate both species as showing 3-4 styles.

Keys and descriptions do not mention the most obvious and consistent distinctions relating to stylar shape and stigmatic structure, which is positioning of styles and shape of the stigma. Attempting to show what I observe in fresh flowers, I’ve removed anthers and petals from flowers of several plants, both specimens under cultivation and wild-collected material. I’ll amplify this catalog of pistils as flowers and time are available. (Note also that my identifications are modestly-tentative, especially with Harperi.)

Hypericum tetrapetalum (Gulf County), showing 3 styles
Pistil from a different specimen of Hypericum tetrapetalum, showing 3 styles
Pistil from fresh flower of Hypericum tetrapetalum (ANF), showing two or three connate styles surmounted by a single stigma (mm scale to right)
Pistil from Hypericum crux-andreae (ANF), showing 3 styles
Pistil of Hypericum suffruticosum (ANF), showing 3 styles
Hypericum suffruticosum, cultivated plant from ANF Tower site, showing 3 styles
Hypericum hypericoides, showing 2 short styles (ANF, SR65 & FSR100)
Pistil of Hypericum fasciculatum sensu lato (Box R), showing a single attenuated style
Hypericum brachyphyllum, note the twist in the ovary…
Pistil of Hypericum galioides (Calhoun County)
Hypericum cistifolium also shows a single style

While most woody species produce erect or arching filiform, tapering styles ending in small stigmas, several plants (apparently the herbaceous and non-woody types) have prominently-capitate or flabelliform stigmas on spreading to almost recurved styles. The photographs below document this curiosity, suggesting the relationship between Setosum and Harperi extends beyond habit and flower size.

Pistil from fresh flower of Hypericum setosum (ANF), showing 3 spreading styles with capitate stigmas (mm scale to right)
Pistil of Hypericum harperi, showing long, flaring styles with capitate stigmas

Note the especially-long styles of Harperi, illustrated in the photograph below:

Style of Hypericum harperi, which stretches 4-5 mm long (see scale along the top left side)

Similarly, stigmas of Hypericum gentianoides and Hypericum mutilum are capitate. In the sample I examined, Gentianoides styles are almost as long as the ovary, while Mutilum styles are short and stout, less than half the height of the ovary.

Pistil of Hypericum gentianoides, total length under 2 mm
Pistil of Hypericum mutilum, total length 1-2 mm

The Back Story

In modern times, few people have “owned” an entire genus as thoroughly as Norman Keith Bonner Robson dominated Hypericum taxonomy. Having completed his Ph.D. thesis on an aspect of these plants at Edinburgh in 1956, he continued his research at London’s Natural History Museum, embarking eventually on a monograph of the entire genus, a massive undertaking – a lifetime job.  Over the 35 years from 1977 to 2012, Robson published his work in installments, treating 490 species worldwide.  What’s particularly astonishing is that the bulk of this work was a “retirement” project, in that Britain had a requisite retirement age of 60 (Robson was born in 1928, with forced retirement in 1988).  He died in September, 2021, at 92 years of age.

But Robson was neither first nor last.  The ISB Plant Atlas lists 44 synonyms (duplicate or invalid names) for the genus, 19 of which relate to the work of Édouard Spach (1801-1879).  Spach, a French botanist, trained with A.L. de Jussieu in Paris and worked during his career as assistant & protégé to Mirbel (considered the founder of Plant Cytology).  In a single publication, “Conspectus Monographiae Hypericacearum” (Annales des Sciences Naturalles, Bot., ser. 2. 5: 364. 1836), Spach described 16 new genera that now are considered synonymous with Hypericum. Three decades later, in 1868, Jules Pierre Fourreau recognized three other genera using Spach’s section names, all of which today are considered synonyms to Hypericum.  

Not to be left out, the colorful Constantine Rafinesque studied Hypericum, naming five new genera that now have fallen into synonymy, more or less.  While Robson’s treatment for Flora of North America and the 2015 Flora of Florida accept Rafinesque’s genus Triadenum, the ISB Florida Atlas continues to subsume the genus to Hypericum.  Easy come, easy go.

My capacity to compare these plants has been greatly-augmented through the opportunity to cultivate them side-by-side here on St. George Island. Some plants were available through native plant nurseries, but others were harvested under permit from Box R WMA and Apalachicola National Forest.

Thanks to Jerry Pitts, Box R Manager, and Toni Brannon, Regional Permits, for assistance in obtaining permits and access to the Box R WMA, Apalachicola, FL

Thanks to Ruby Roberts and Forest Supervisor Kelly Russell for permission to study and voucher plants in Apalachicola National Forest.

Thanks to Mark Kiser for permission to study and document plant life in Tate’s Hell State Forest

Last Updated – 23 August 2023

Flora – Main Index Page

%d bloggers like this: